The invention relates to a mechanical coupling and particularly to a coupling particularly adapted to couple a valve actuator to a valve. Although the apparatus has particular application to valves it will be understood that the apparatus of the invention may also be used to couple other members.
The prior art includes a wide variety of mechanical couplings. It is an object of the invention to provide apparatus which will permit the connection of a range of valve shaft sizes to an actuator of one particular size. Thus, a valve manufacturer need not inventory, for example four different size valve actuators to fit respectively four different size valve shafts. Instead he may inventory a single actuator and four different valve couplings.
It is an object of the invention to provide a coupling apparatus which enable the quick and easy installation of an actuator on a valve body and particularly with a single bolt.
Another object of the invention is to provide apparatus that couples a drive and a driven member such as an actuator and a valve shaft with an absolute minimum of lost motion so that the driven member, such as the valve, is accurately controlled.
A further object of the invention is to provide embodiments of the invention that have a minimum number of parts.
Still another object of the invention is to provide apparatus which will mount the valve actuator closely to the valve to minimize vibration which may be associated with a relatively heavy actuator which is cantilevered out from the valve body. This will minimize vibrational loads on the duct or pipe to which the valve body is attached.
It is yet another object of the invention to provide apparatus which is may be manufactured at less expense than prior art mechanisms.